SNAKE

also called serpent, any member of the reptile group Serpentes, with the Sauria (lizards) and Amphisbaenia (wormlike amphisbaenians), one of the three suborders of the order Squamata. Their most distinctive featureslack of limbs (vestiges are present in a few members), reduction or absence of one lung, and elongation of internal organsare associated with the long, slender body shapes. They are widely known and a much misunderstood group. Arms and legs gone, no ears, only one functional lung, voiceless, eyelids missinga human being in such condition would be institutionalized and under constant care. Snakes have not only survived these losses but have become highly successful in a great variety of ecological roles. Fearless, independent, and usually solitary, the snake has capitalized upon these apparent deficiencies to become an efficient second- and third-level predator, focussing perhaps 70 percent of its existence on tracking down, catching, and digesting its living prey. The elongate, limbless body of the snake permits it to be soundless in motion, invisible at rest, and almost unlimited in its access to hiding places, such as nests, tree holes, crevices, brier patches, gopher tunnels, and other shelters where small vertebrated animals seem to feel themselves safe from their enemies. Most of the remainder of the snake's existence is dedicated to continued survival in an antagonistic world that is usually either too hot or too cold and is full of other organisms challenging the snake's right to live. With its body temperature almost totally dependent upon the surroundings, the snake must seek out both nightly and seasonal resting places where rising temperatures eventually can be relied upon to rekindle its abilities to move, to sense, and to reproduce. Reproduction demands only a few percent of the male snake's existence, for it consists of little more than a sudden burst of highly seasonal activity followed by an immediate return to the more pressing activities of food search. The female devotes slightly more time to reproductive activities, because she must eventually seek out a suitable place to deposit the eggs or to give birth to a usually good-sized brood. This, too, however, is an act of short duration, followed immediately by return to the continuing problems of daily existence. Snakes are found around the world in practically every kind of habitat and in all regions except near the poles. They are not successful competitors with man, and only a few diminutive species with very secretive habits find it possible to share living space with humans. When man moves in, practically all reptiles share the fate of large mammals and predatory birdsthey must move out or die, because man is not and never has been a particularly good coexisting species except with those organisms that he bends to his will, such as corn or horses, or with those capable of capitalizing upon his presence, such as pigeons and rats. Of the reptiles, the snake is the most distasteful to man, and snake species are quickly wiped out. In rural areas, man pays the penalty for this eradication in an inevitable increase in the natural prey of the snakes, including rats, mice, and other rodents. also called Serpent, a reptile (suborder Serpentes) whose most distinctive featureslack of limbs (vestiges are present in a few snakes), reduction or absence of one lung, and elongation of internal organsare associated with the long, slender body shape. Snakes are closely related to lizards (suborder Sauria), with which they constitute the order Squamata and from which they are believed to have evolved. Certain lizards, in fact, closely resemble snakes, being long, slender, and limbless, but they are easily distinguished from snakes by the possession of eyelids and external ear openings. Snakes range in size from about 12 centimetres (5 inches) to about 9.5 metres (31 feet). The size limits are difficult to ascertain with accuracy because the smallest species, the thread snakes of the Middle East, are secretive, poorly known burrowers, and the largest, the reticulated python (Python reticulatus) of Asia and the anaconda (Eunectes murinus; see ) of South America, rarely survive to reach maximum size. Snakes grow continuously, though at decreasing rates, throughout their lives. Snakes inhabit all continents, but few species are found in regions with long winters, and the greatest diversity occurs in the tropics. They do not, however, occupy many of the world's islands. Additional reading Carl Gans et al. (eds.), Biology of the Reptilia (1969 ), a multivolume work, made up of contributions by specialists, that summarizes current knowledge about the class Reptilia, with emphasis on morphology, embryology and physiology, and ecology and behaviour; George A. Boulenger, Catalogue of the Snakes in the British Museum (Natural History), 3 vol. (189396, reissued 3 vol. in 2, 1961), a classic work, the only attempt ever made in the English language to list, describe, and help identify all the snakes of the world; Garth Underwood, A Contribution to the Classification of Snakes (1967), a highly technical discussion of relationships among the various kinds of snakes; James A. Peters, Dictionary of Herpetology (1964), contains extensive information about snakes and other reptiles, in a readily accessible form; Roger Conant and Joseph T. Collins, A Field Guide to Reptiles and Amphibians: Eastern and Central America, 3rd ed. (1991); Robert C. Stebbins, A Field Guide to Western Reptiles and Amphibians, 2nd rev. ed. (1985), extensively illustrated manuals for field identification of snakes, as well as other reptiles; Clifford H. Pope, The Giant Snakes (1961), an entertaining discussion of the very large snakes, and Snakes Alive and How They Live (1937, reissued 1965), although somewhat outdated, still a readable account of snake natural history; Albert H. and Anna A. Wright, Handbook of Snakes of the United States and Canada, 2 vol. (1957), detailed descriptions of all the kinds of snakes known on the North American continent, with many photographs; Coleman J. Goin, Olive B. Goin, and George R. Zug, Introduction to Herpetology, 3rd ed. (1978), a textbook designed for undergraduate classes at the college level; Karl P. Schmidt and Robert F. Inger, Living Reptiles of the World, pp. 175279 (1957, reissued 1967), a popular account, aimed at the general public, profusely illustrated with colour photographs; Ramona and Desmond Morris, Men and Snakes (1965), a thorough review of man's relationships with snakes, including culture, mythology, medicine, and exploitation; H.W. Parker, Natural History of Snakes (1965), one of the handbook guides to the British Museum, and Snakes (1963), a factual account of the general biology of snakes; Laurence M. Klauber, Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind, 2 vol. (1956; abridged ed., 1982), a thorough summary, not only of rattlesnakes but of all snakes, their biology and relationships with man; Hobart M. Smith, Snakes As Pets, 4th ed. (1980), a guide to the care and feeding of snakes in captivity; James A. Oliver, Snakes in Fact and Fiction (1958, reissued 1963), a popular account of the snake, with both true and imaginative stories about size, food, numbers, and other bits of natural history; Wolfgang Bcherl, E.E. Buckley, and V. Deulofeu (eds.), Venomous Animals and Their Venoms, 3 vol. (196871), a discussion of the classification, distribution, and biology of venomous snakes, with detailed discussions of their venoms as well as treatment of snakebite; Sherman A. Minton, Jr., and Madge R. Minton, Venomous Reptiles, rev. ed. (1980), an entertaining and often anecdotal account of venoms, venomous reptiles, their bites and the treatment of bites, and the intricate relationships of snakes with man and his cultures; Tony Phelps, Poisonous Snakes, rev. ed. (1989), a treatment of the rear-fanged colubrids, the elapids, and the vipers.